/*
 *
 * NOTE: The client side of hack.chat is currently in development,
 * a new, more modern but still minimal version will be released
 * soon. As a result of this, the current code has been deprecated
 * and will not actively be updated.
 *
*/

// initialize markdown engine
var markdownOptions = {
	html: false,
	xhtmlOut: false,
	breaks: true,
	langPrefix: '',
	linkify: true,
	linkTarget: '_blank" rel="noreferrer',
	typographer:  true,
	quotes: `""''`,

	doHighlight: true,
	highlight: function (str, lang) {
		if (!markdownOptions.doHighlight || !window.hljs) { return ''; }

		if (lang && hljs.getLanguage(lang)) {
			try {
				return hljs.highlight(lang, str).value;
			} catch (__) {}
		}

		try {
			return hljs.highlightAuto(str).value;
		} catch (__) {}

		return '';
	}
};

var md = new Remarkable('full', markdownOptions);

// image handler
var allowImages = false;
var imgHostWhitelist = [
	'i.imgur.com',
	'imgur.com',
];

function getDomain(link) {
	var a = document.createElement('a');
	a.href = link;
	return a.hostname;
}

function isWhiteListed(link) {
	return imgHostWhitelist.indexOf(getDomain(link)) !== -1;
}

md.renderer.rules.image = function (tokens, idx, options) {
	var src = Remarkable.utils.escapeHtml(tokens[idx].src);

	if (isWhiteListed(src) && allowImages) {
		var imgSrc = ' src="' + Remarkable.utils.escapeHtml(tokens[idx].src) + '"';
		var title = tokens[idx].title ? (' title="' + Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(tokens[idx].title)) + '"') : '';
		var alt = ' alt="' + (tokens[idx].alt ? Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(Remarkable.utils.unescapeMd(tokens[idx].alt))) : '') + '"';
		var suffix = options.xhtmlOut ? ' /' : '';
		var scrollOnload = isAtBottom() ? ' onload="window.scrollTo(0, document.body.scrollHeight)"' : '';
		return '<a href="' + src + '" target="_blank" rel="noreferrer"><img' + scrollOnload + imgSrc + alt + title + suffix + '></a>';
	}

  return '<a href="' + src + '" target="_blank" rel="noreferrer">' + Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(src)) + '</a>';
};

md.renderer.rules.link_open = function (tokens, idx, options) {
	var title = tokens[idx].title ? (' title="' + Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(tokens[idx].title)) + '"') : '';
  var target = options.linkTarget ? (' target="' + options.linkTarget + '"') : '';
  return '<a rel="noreferrer" onclick="return verifyLink(this)" href="' + Remarkable.utils.escapeHtml(tokens[idx].href) + '"' + title + target + '>';
};

md.renderer.rules.text = function(tokens, idx) {
	tokens[idx].content = Remarkable.utils.escapeHtml(tokens[idx].content);

	if (tokens[idx].content.indexOf('?') !== -1) {
		tokens[idx].content = tokens[idx].content.replace(/(^|\s)(\?)\S+?(?=[,.!?:)]?\s|$)/gm, function(match) {
			var channelLink = Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(match.trim()));
			var whiteSpace = '';
			if (match[0] !== '?') {
				whiteSpace = match[0];
			}
			return whiteSpace + '<a href="' + channelLink + '" target="_blank">' + channelLink + '</a>';
		});
	}

  return tokens[idx].content;
};

md.use(remarkableKatex);

function verifyLink(link) {
	var linkHref = Remarkable.utils.escapeHtml(Remarkable.utils.replaceEntities(link.href));
	if (linkHref !== link.innerHTML) {
		return confirm('Warning, please verify this is where you want to go: ' + linkHref);
	}

	return true;
}

var verifyNickname = function (nick) {
	return /^[a-zA-Z0-9_]{1,24}$/.test(nick);
}

var frontpage = [
	"                            _           _         _       _   ",
	"                           | |_ ___ ___| |_   ___| |_ ___| |_ ",
	"                           |   |_ ||  _| '_| |  _|   |_ ||  _|",
	"                           |_|_|__/|___|_,_|.|___|_|_|__/|_|  ",
	"",
	"",
	"Welcome to hack.chat, a minimal, distraction-free chat application.",
	"Channels are created, joined and shared with the url, create your own channel by changing the text after the question mark.",
	"If you wanted your channel name to be 'your-channel': https://hack.chat/?your-channel",
	"There are no channel lists, so a secret channel name can be used for private discussions.",
	"",
	"Here are some pre-made channels you can join:",
	"?lounge ?meta",
	"?math ?physics ?chemistry",
	"?technology ?programming",
	"?games ?banana",
	"And here's a random one generated just for you: ?" + Math.random().toString(36).substr(2, 8),
	"",
	"Formatting:",
	"Whitespace is preserved, so source code can be pasted verbatim.",
	"Surround LaTeX with a dollar sign for inline style $\\zeta(2) = \\pi^2/6$, and two dollars for display. $$\\int_0^1 \\int_0^1 \\frac{1}{1-xy} dx dy = \\frac{\\pi^2}{6}$$",
	"For syntax highlight, wrap the code like: ```<language> <the code>``` where <language> is any known programming language.",
	"",
	"Current Github: https://github.com/hack-chat",
	"Legacy GitHub: https://github.com/AndrewBelt/hack.chat",
	"",
	"Bots, Android clients, desktop clients, browser extensions, docker images, programming libraries, server modules and more:",
	"https://github.com/hack-chat/3rd-party-software-list",
	"",
	"Server and web client released under the WTFPL and MIT open source license.",
	"No message history is retained on the hack.chat server."
].join("\n");

function $(query) {
	return document.querySelector(query);
}

function localStorageGet(key) {
	try {
		return window.localStorage[key]
	} catch (e) { }
}

function localStorageSet(key, val) {
	try {
		window.localStorage[key] = val
	} catch (e) { }
}

var ws;
var myNick = localStorageGet('my-nick') || '';
var myChannel = window.location.search.replace(/^\?/, '');
var lastSent = [""];
var lastSentPos = 0;

/** Notification switch and local storage behavior **/
var notifySwitch = document.getElementById("notify-switch")
var notifySetting = localStorageGet("notify-api")
var notifyPermissionExplained = 0; // 1 = granted msg shown, -1 = denied message shown

// Inital request for notifications permission
function RequestNotifyPermission() {
	try {
		var notifyPromise = Notification.requestPermission();
		if (notifyPromise) {
			notifyPromise.then(function (result) {
				console.log("Hack.Chat notification permission: " + result);
				if (result === "granted") {
					if (notifyPermissionExplained === 0) {
						pushMessage({
							cmd: "chat",
							nick: "*",
							text: "Notifications permission granted.",
							time: null
						});
						notifyPermissionExplained = 1;
					}
					return false;
				} else {
					if (notifyPermissionExplained === 0) {
						pushMessage({
							cmd: "chat",
							nick: "*",
							text: "Notifications permission denied, you won't be notified if someone @mentions you.",
							time: null
						});
						notifyPermissionExplained = -1;
					}
					return true;
				}
			});
		}
	} catch (error) {
		pushMessage({
			cmd: "chat",
			nick: "*",
			text: "Unable to create a notification.",
			time: null
		});
		console.error("An error occured trying to request notification permissions. This browser might not support desktop notifications.\nDetails:")
		console.error(error)
		return false;
	}
}

// Update localStorage with value of checkbox
notifySwitch.addEventListener('change', (event) => {
	if (event.target.checked) {
		RequestNotifyPermission();
	}
	localStorageSet("notify-api", notifySwitch.checked)
})
// Check if localStorage value is set, defaults to OFF
if (notifySetting === null) {
	localStorageSet("notify-api", "false")
	notifySwitch.checked = false
}
// Configure notifySwitch checkbox element
if (notifySetting === "true" || notifySetting === true) {
	notifySwitch.checked = true
} else if (notifySetting === "false" || notifySetting === false) {
	notifySwitch.checked = false
}

/** Sound switch and local storage behavior **/
var soundSwitch = document.getElementById("sound-switch")
var notifySetting = localStorageGet("notify-sound")

// Update localStorage with value of checkbox
soundSwitch.addEventListener('change', (event) => {
	localStorageSet("notify-sound", soundSwitch.checked)
})
// Check if localStorage value is set, defaults to OFF
if (notifySetting === null) {
	localStorageSet("notify-sound", "false")
	soundSwitch.checked = false
}
// Configure soundSwitch checkbox element
if (notifySetting === "true" || notifySetting === true) {
	soundSwitch.checked = true
} else if (notifySetting === "false" || notifySetting === false) {
	soundSwitch.checked = false
}

// Create a new notification after checking if permission has been granted
function spawnNotification(title, body) {
	// Let's check if the browser supports notifications
	if (!("Notification" in window)) {
		console.error("This browser does not support desktop notification");
	} else if (Notification.permission === "granted") { // Check if notification permissions are already given
		// If it's okay let's create a notification
		var options = {
			body: body,
			icon: "/favicon-96x96.png"
		};
		var n = new Notification(title, options);
	}
	// Otherwise, we need to ask the user for permission
	else if (Notification.permission !== "denied") {
		if (RequestNotifyPermission()) {
			var options = {
				body: body,
				icon: "/favicon-96x96.png"
			};
			var n = new Notification(title, options);
		}
	} else if (Notification.permission == "denied") {
		// At last, if the user has denied notifications, and you
		// want to be respectful, there is no need to bother them any more.
	}
}

function notify(args) {
	// Spawn notification if enabled
	if (notifySwitch.checked) {
		spawnNotification("?" + myChannel + "  —  " + args.nick, args.text)
	}

	// Play sound if enabled
	if (soundSwitch.checked) {
		var soundPromise = document.getElementById("notify-sound").play();
		if (soundPromise) {
			soundPromise.catch(function (error) {
				console.error("Problem playing sound:\n" + error);
			});
		}
	}
}

function join(channel) {
	if (document.domain == 'hack.chat') {
		// For https://hack.chat/
		ws = new WebSocket('wss://hack.chat/chat-ws');
	} else {
		// for local installs
		var protocol = location.protocol === 'https:' ? 'wss:' : 'ws:'
		// if you changed the port during the server config, change 'wsPath'
		// to the new port (example: ':8080')
		// if you are reverse proxying, change 'wsPath' to the new location
		// (example: '/chat-ws')
		var wsPath = ':6060';
		ws = new WebSocket(protocol + '//' + document.domain + wsPath);
	}

	var wasConnected = false;

	ws.onopen = function () {
		var shouldConnect = true;
		if (!wasConnected) {
			if (location.hash) {
				myNick = location.hash.substr(1);
			} else {
				var newNick = prompt('Nickname:', myNick);
				if (newNick !== null) {
					myNick = newNick;
				} else {
					// The user cancelled the prompt in some manner
					shouldConnect = false;
				}
			}
		}

		if (myNick && shouldConnect) {
			localStorageSet('my-nick', myNick);
			send({ cmd: 'join', channel: channel, nick: myNick });
		}

		wasConnected = true;
	}

	ws.onclose = function () {
		if (wasConnected) {
			pushMessage({ nick: '!', text: "Server disconnected. Attempting to reconnect. . ." });
		}

		window.setTimeout(function () {
			join(channel);
		}, 2000);
	}

	ws.onmessage = function (message) {
		var args = JSON.parse(message.data);
		var cmd = args.cmd;
		var command = COMMANDS[cmd];
		command.call(null, args);
	}
}

var COMMANDS = {
	chat: function (args) {
		if (ignoredUsers.indexOf(args.nick) >= 0) {
			return;
		}
		pushMessage(args);
	},

	info: function (args) {
		args.nick = '*';
		pushMessage(args);
	},

	warn: function (args) {
		args.nick = '!';
		pushMessage(args);
	},

	onlineSet: function (args) {
		var nicks = args.nicks;

		usersClear();

		nicks.forEach(function (nick) {
			userAdd(nick);
		});

		pushMessage({ nick: '*', text: "Users online: " + nicks.join(", ") })
	},

	onlineAdd: function (args) {
		var nick = args.nick;

		userAdd(nick);

		if ($('#joined-left').checked) {
			pushMessage({ nick: '*', text: nick + " joined" });
		}
	},

	onlineRemove: function (args) {
		var nick = args.nick;

		userRemove(nick);

		if ($('#joined-left').checked) {
			pushMessage({ nick: '*', text: nick + " left" });
		}
	}
}

function pushMessage(args) {
	// Message container
	var messageEl = document.createElement('div');

	if (
		typeof (myNick) === 'string' && (
			args.text.match(new RegExp('@' + myNick.split('#')[0] + '\\b', "gi")) ||
			((args.type === "whisper" || args.type === "invite") && args.from)
		)
	) {
		notify(args);
	}

	messageEl.classList.add('message');

	if (verifyNickname(myNick) && args.nick == myNick) {
		messageEl.classList.add('me');
	} else if (args.nick == '!') {
		messageEl.classList.add('warn');
	} else if (args.nick == '*') {
		messageEl.classList.add('info');
	} else if (args.admin) {
		messageEl.classList.add('admin');
	} else if (args.mod) {
		messageEl.classList.add('mod');
	}

	// Nickname
	var nickSpanEl = document.createElement('span');
	nickSpanEl.classList.add('nick');
	messageEl.appendChild(nickSpanEl);

	if (args.trip) {
		var tripEl = document.createElement('span');
		tripEl.textContent = args.trip + " ";
		tripEl.classList.add('trip');
		nickSpanEl.appendChild(tripEl);
	}

	if (args.nick) {
		var nickLinkEl = document.createElement('a');
		nickLinkEl.textContent = args.nick;

		nickLinkEl.onclick = function () {
			insertAtCursor("@" + args.nick + " ");
			$('#chatinput').focus();
		}

		var date = new Date(args.time || Date.now());
		nickLinkEl.title = date.toLocaleString();
		nickSpanEl.appendChild(nickLinkEl);
	}

	// Text
	var textEl = document.createElement('p');
	textEl.classList.add('text');
	textEl.innerHTML = md.render(args.text);

	messageEl.appendChild(textEl);

	// Scroll to bottom
	var atBottom = isAtBottom();
	$('#messages').appendChild(messageEl);
	if (atBottom) {
		window.scrollTo(0, document.body.scrollHeight);
	}

	unread += 1;
	updateTitle();
}

function insertAtCursor(text) {
	var input = $('#chatinput');
	var start = input.selectionStart || 0;
	var before = input.value.substr(0, start);
	var after = input.value.substr(start);

	before += text;
	input.value = before + after;
	input.selectionStart = input.selectionEnd = before.length;

	updateInputSize();
}

function send(data) {
	if (ws && ws.readyState == ws.OPEN) {
		ws.send(JSON.stringify(data));
	}
}

var windowActive = true;
var unread = 0;

window.onfocus = function () {
	windowActive = true;

	updateTitle();
}

window.onblur = function () {
	windowActive = false;
}

window.onscroll = function () {
	if (isAtBottom()) {
		updateTitle();
	}
}

function isAtBottom() {
	return (window.innerHeight + window.scrollY) >= (document.body.scrollHeight - 1);
}

function updateTitle() {
	if (windowActive && isAtBottom()) {
		unread = 0;
	}

	var title;
	if (myChannel) {
		title = "?" + myChannel;
	} else {
		title = "hack.chat";
	}

	if (unread > 0) {
		title = '(' + unread + ') ' + title;
	}

	document.title = title;
}

$('#footer').onclick = function () {
	$('#chatinput').focus();
}

$('#chatinput').onkeydown = function (e) {
	if (e.keyCode == 13 /* ENTER */ && !e.shiftKey) {
		e.preventDefault();

		// Submit message
		if (e.target.value != '') {
			var text = e.target.value;
			e.target.value = '';

			send({ cmd: 'chat', text: text });

			lastSent[0] = text;
			lastSent.unshift("");
			lastSentPos = 0;

			updateInputSize();
		}
	} else if (e.keyCode == 38 /* UP */) {
		// Restore previous sent messages
		if (e.target.selectionStart === 0 && lastSentPos < lastSent.length - 1) {
			e.preventDefault();

			if (lastSentPos == 0) {
				lastSent[0] = e.target.value;
			}

			lastSentPos += 1;
			e.target.value = lastSent[lastSentPos];
			e.target.selectionStart = e.target.selectionEnd = e.target.value.length;

			updateInputSize();
		}
	} else if (e.keyCode == 40 /* DOWN */) {
		if (e.target.selectionStart === e.target.value.length && lastSentPos > 0) {
			e.preventDefault();

			lastSentPos -= 1;
			e.target.value = lastSent[lastSentPos];
			e.target.selectionStart = e.target.selectionEnd = 0;

			updateInputSize();
		}
	} else if (e.keyCode == 27 /* ESC */) {
		e.preventDefault();

		// Clear input field
		e.target.value = "";
		lastSentPos = 0;
		lastSent[lastSentPos] = "";

		updateInputSize();
	} else if (e.keyCode == 9 /* TAB */) {
		// Tab complete nicknames starting with @

		if (e.ctrlKey) {
			// Skip autocompletion and tab insertion if user is pressing ctrl
			// ctrl-tab is used by browsers to cycle through tabs
			return;
		}
		e.preventDefault();

		var pos = e.target.selectionStart || 0;
		var text = e.target.value;
		var index = text.lastIndexOf('@', pos);

		var autocompletedNick = false;

		if (index >= 0) {
			var stub = text.substring(index + 1, pos).toLowerCase();
			// Search for nick beginning with stub
			var nicks = onlineUsers.filter(function (nick) {
				return nick.toLowerCase().indexOf(stub) == 0
			});

			if (nicks.length > 0) {
				autocompletedNick = true;
				if (nicks.length == 1) {
					insertAtCursor(nicks[0].substr(stub.length) + " ");
				}
			}
		}

		// Since we did not insert a nick, we insert a tab character
		if (!autocompletedNick) {
			insertAtCursor('\t');
		}
	}
}

function updateInputSize() {
	var atBottom = isAtBottom();

	var input = $('#chatinput');
	input.style.height = 0;
	input.style.height = input.scrollHeight + 'px';
	document.body.style.marginBottom = $('#footer').offsetHeight + 'px';

	if (atBottom) {
		window.scrollTo(0, document.body.scrollHeight);
	}
}

$('#chatinput').oninput = function () {
	updateInputSize();
}

updateInputSize();

/* sidebar */

$('#sidebar').onmouseenter = $('#sidebar').ontouchstart = function (e) {
	$('#sidebar-content').classList.remove('hidden');
	$('#sidebar').classList.add('expand');
	e.stopPropagation();
}

$('#sidebar').onmouseleave = document.ontouchstart = function (event) {
	var e = event.toElement || event.relatedTarget;
	try {
		if (e.parentNode == this || e == this) {
	     return;
	  }
	} catch (e) { return; }

	if (!$('#pin-sidebar').checked) {
		$('#sidebar-content').classList.add('hidden');
		$('#sidebar').classList.remove('expand');
	}
}

$('#clear-messages').onclick = function () {
	// Delete children elements
	var messages = $('#messages');
	messages.innerHTML = '';
}

// Restore settings from localStorage

if (localStorageGet('pin-sidebar') == 'true') {
	$('#pin-sidebar').checked = true;
	$('#sidebar-content').classList.remove('hidden');
}

if (localStorageGet('joined-left') == 'false') {
	$('#joined-left').checked = false;
}

if (localStorageGet('parse-latex') == 'false') {
	$('#parse-latex').checked = false;
	md.inline.ruler.disable([ 'katex' ]);
	md.block.ruler.disable([ 'katex' ]);
}

$('#pin-sidebar').onchange = function (e) {
	localStorageSet('pin-sidebar', !!e.target.checked);
}

$('#joined-left').onchange = function (e) {
	localStorageSet('joined-left', !!e.target.checked);
}

$('#parse-latex').onchange = function (e) {
	var enabled = !!e.target.checked;
	localStorageSet('parse-latex', enabled);
	if (enabled) {
		md.inline.ruler.enable([ 'katex' ]);
		md.block.ruler.enable([ 'katex' ]);
	} else {
		md.inline.ruler.disable([ 'katex' ]);
		md.block.ruler.disable([ 'katex' ]);
	}
}

if (localStorageGet('syntax-highlight') == 'false') {
	$('#syntax-highlight').checked = false;
	markdownOptions.doHighlight = false;
}

$('#syntax-highlight').onchange = function (e) {
	var enabled = !!e.target.checked;
	localStorageSet('syntax-highlight', enabled);
	markdownOptions.doHighlight = enabled;
}

if (localStorageGet('allow-imgur') == 'false') {
	$('#allow-imgur').checked = false;
	allowImages = false;
}

$('#allow-imgur').onchange = function (e) {
	var enabled = !!e.target.checked;
	localStorageSet('allow-imgur', enabled);
	allowImages = enabled;
}

// User list
var onlineUsers = [];
var ignoredUsers = [];

function userAdd(nick) {
	var user = document.createElement('a');
	user.textContent = nick;

	user.onclick = function (e) {
		userInvite(nick)
	}

	var userLi = document.createElement('li');
	userLi.appendChild(user);
	$('#users').appendChild(userLi);
	onlineUsers.push(nick);
}

function userRemove(nick) {
	var users = $('#users');
	var children = users.children;

	for (var i = 0; i < children.length; i++) {
		var user = children[i];
		if (user.textContent == nick) {
			users.removeChild(user);
		}
	}

	var index = onlineUsers.indexOf(nick);
	if (index >= 0) {
		onlineUsers.splice(index, 1);
	}
}

function usersClear() {
	var users = $('#users');

	while (users.firstChild) {
		users.removeChild(users.firstChild);
	}

	onlineUsers.length = 0;
}

function userInvite(nick) {
	send({ cmd: 'invite', nick: nick });
}

function userIgnore(nick) {
	ignoredUsers.push(nick);
}

/* color scheme switcher */

var schemes = [
	'android',
	'android-white',
	'atelier-dune',
	'atelier-forest',
	'atelier-heath',
	'atelier-lakeside',
	'atelier-seaside',
	'banana',
	'bright',
	'bubblegum',
	'chalk',
	'default',
	'eighties',
	'fresh-green',
	'greenscreen',
	'hacker',
	'maniac',
	'mariana',
	'military',
	'mocha',
	'monokai',
	'nese',
	'ocean',
	'omega',
	'pop',
	'railscasts',
	'solarized',
	'tk-night',
	'tomorrow'
];

var highlights = [
	'agate',
	'androidstudio',
	'atom-one-dark',
	'darcula',
	'github',
	'rainbow',
	'tk-night',
	'tomorrow',
	'xcode',
	'zenburn'
]

var currentScheme = 'atelier-dune';
var currentHighlight = 'darcula';

function setScheme(scheme) {
	currentScheme = scheme;
	$('#scheme-link').href = "schemes/" + scheme + ".css";
	localStorageSet('scheme', scheme);
}

function setHighlight(scheme) {
	currentHighlight = scheme;
	$('#highlight-link').href = "vendor/hljs/styles/" + scheme + ".min.css";
	localStorageSet('highlight', scheme);
}

// Add scheme options to dropdown selector
schemes.forEach(function (scheme) {
	var option = document.createElement('option');
	option.textContent = scheme;
	option.value = scheme;
	$('#scheme-selector').appendChild(option);
});

highlights.forEach(function (scheme) {
	var option = document.createElement('option');
	option.textContent = scheme;
	option.value = scheme;
	$('#highlight-selector').appendChild(option);
});

$('#scheme-selector').onchange = function (e) {
	setScheme(e.target.value);
}

$('#highlight-selector').onchange = function (e) {
	setHighlight(e.target.value);
}

// Load sidebar configaration values from local storage if available
if (localStorageGet('scheme')) {
	setScheme(localStorageGet('scheme'));
}

if (localStorageGet('highlight')) {
	setHighlight(localStorageGet('highlight'));
}

$('#scheme-selector').value = currentScheme;
$('#highlight-selector').value = currentHighlight;

/* main */

if (myChannel == '') {
	pushMessage({ text: frontpage });
	$('#footer').classList.add('hidden');
	$('#sidebar').classList.add('hidden');
} else {
	join(myChannel);
}
